1. Field
The present invention relates to a refrigerator, and, more particularly, to a refrigerator capable of accurately sensing the temperature of, for example, a beverage stored in a supercooling compartment and whether the beverage is in a supercooled state, and a control method thereof.
2. Description of the Related Art
A refrigerator is an apparatus which supplies cool air produced by a refrigerating unit to a storage compartment to maintain freshness of various food products for a long period of time. In a case of appropriately adjusting the temperature of the compartment of the refrigerator, a liquid beverage can be maintained in a supercooled state, and a user can use the supercooled beverage to obtain a beverage which is not completely frozen or not completely melted (hereinafter, referred to as ‘slush’).
The liquid beverage is generally changed to a solid phase when its temperature decreases below its freezing point under 1 atmospheric pressure. However, in some circumstances, the beverage is not changed into the solid phase and is maintained in a supercooled state. Such a supercooled state in which liquid is not frozen, even below the freezing point, is referred to as a metastable state in thermodynamics. Since the liquid in the metastable state is not stable, the beverage instantaneously undergoes a phase transition to the solid phase when there is ambient disturbance such as impact or vibration. When there is a phase transition, the beverage or food is changed into a frozen state from the supercooled state.
As an example, a refrigerator capable of determining whether the supercooled state is achieved is disclosed in Korean Patent Registration No. 10-756712.
This reference discloses a refrigerator including a temperature sensor which measures the temperature of the supercooling compartment such that the temperature of the supercooling compartment is continuously sensed by the temperature sensor, wherein when the temperature continuously increases for a specific time period or more, or when the temperature of the supercooling compartment is stabilized after the temperature increases by a predetermined value, a control unit determines that the supercooled state is canceled and notifies the outside through a display unit, and a method of determining an end of the supercooled state of the refrigerator.
In the conventional refrigerator disclosed in this reference, since the temperature sensor is disposed at an upper portion of the supercooling compartment while being spaced from the liquid beverage stored in the supercooling compartment, there is a problem that the temperature of the liquid beverage or the like cannot be accurately measured.
Further, the temperature of the supercooling compartment is changed due to opening/closing of an adjuster such as a valve and a damper, which adjusts cool air of the storage compartment to flow into the supercooling compartment, opening/closing of the supercooling compartment, or the like. A method of determining an end of the supercooled state of the conventional refrigerator has a problem of misdetermination in which it is determined that the supercooled state of the supercooled object is canceled when the temperature continuously increases for a specific time period, or also when the temperature is stabilized after the temperature increases by a predetermined value due to temperature variation of the supercooling compartment.
Further, in the method of determining cancellation of the supercooled state of the conventional refrigerator, which is disclosed in the document, only cancellation of the supercooled state can be determined and it is impossible to determine whether supercooling is achieved and fails to be achieved.